Wellington's streets have been busier than usual in the past few months, with traffic flows showing an increase linked to the improving economy.

The Infometrics Quarterly Economic Monitor revealed that traffic in the city during the year to March increased by 0.8 per cent.

The report, published yesterday, was commissioned by Wellington City Council. Its papers say "the rising traffic flows are consistent with strengthening economic activity", particularly in the construction sector.

"Traffic flows in Wellington city have returned to growth as the city's recovery becomes more entrenched."

Flat traffic flows in Wellington were used by some opponents of the Basin Reserve flyover as a reason for the $90 million project to be mothballed.

An Automobile Association spokesman, Dylan Thomsen, said the number of vehicle kilometres travelled throughout the country had started to rise again after a flat period, new and used car sales were at near record levels this year, and the number of people getting driver licences nationally was well up.

"The peak-hour congestion heading in and out of Wellington also seems to have increased this year, so it's no surprise to see that traffic volumes are rising in Wellington."

The Infometrics report also showed that the number of cars registered in the city increased by 11.4 per cent in the year to March over the previous year. Commercial vehicle registrations were up 18.5 per cent in the same period.

Wellington city's gross domestic product increased 1.7 per cent, lower than the national average increase of 2.5 per cent.

The report also showed that unemployment in Wellington was 6.4 per cent, down from 7.5 per cent a year earlier. However, that is higher than the national average of 6 per cent.

The improving job prospects may have encouraged people to move to Wellington, with net migration to the city over the March year totalling more than 1000 people.